Until recently pressure jet oil burners have proved successful owing to their satisfactory performance and reasonable price. However recent years have seen a change in the standard fuel oils being produced by the oil companies, as a result of many factors, such as the wider diversity of oil sources in the world and changes in the needs of industry for various petroleum-based products. Until recently, light oils (kerosene and gas oil) were produced to the lower tolerance of the specified standard for fuel oils, giving oils which operated in existing pressure jet oil burners with good atomisation. Today the light oils are produced nearer to the upper specified density and viscosity tolerance of the standard for fuel oils. When such oils are used in pressure jet oil burners, problems have arisen due to poor atomisation and bad starting especially at low ambient temperatures. Pressure jet burner manufacturers have suggested that these problems can be overcome by fitting heaters to the oil nozzle assembly. The fine tolerance and small apertures within the nozzles of such burners have led to the need for high degrees of filtration of the oil supply and this has caused problems due to the presence of wax constituents within the oils. Thus, because of the danger of waxing in cold weather, the oil industry has suggested that industrial and domestic installations need to include storage tank heaters and pipework insulation. Naturally, these additional provisions increase the cost of installating oil fired equipment.
There is clearly a need for the development of alternative burners which have a wider operating tolerance and can perform satisfactorily with the fuel oils now available.